Circuit arrangements including two semiconductor switching elements and one freewheeling element can be used for example for driving an inductive load, such as, for example, an electric motor or a solenoid valve. In such a case, a first one of the two switching elements serves for applying a supply voltage to the load, while a second one of the two switching elements together with the freewheeling element forms a freewheeling device that enables a freewheeling current through the load when the first semiconductor switching element is driven in the off state.
An inductive load driven by a circuit arrangement including two semiconductor switching elements and one freewheeling element can also be an inductive storage element in a switching converter. Switching converters serve for converting an input voltage, which can be applied to input terminals, into an output voltage, which can be tapped off at output terminals. There are switching converters which include an inductive storage element, a first semiconductor switching element, a second semiconductor switching element, and a freewheeling element connected in parallel with the second semiconductor switching element. In such switching converters, the first semiconductor switching element serves to apply the input voltage to the inductive storage element in clocked fashion, and the second semiconductor switching element serves to accept a freewheeling current of the inductive storage element during those time durations during which the first semiconductor switching element is turned off. In this case, the freewheeling element accepts the freewheeling current during those time durations during which the first and second semiconductor switching elements are simultaneously turned off.
Known semiconductor switching elements for switching converters are, for example, power transistors, such as, for example, power MOSFET or power IGBT. Known freewheeling elements are diodes, such as, for example, bipolar diodes or Schottky diodes. Such transistors and diodes are integrated in semiconductor bodies (dies) accommodated in a chip housing. During the operation of a switching converter, electrical losses arise in the semiconductor switching elements and the freewheeling element, and can lead to heating of the semiconductor body of the respective component. This heat must be dissipated from the respective chip housing since otherwise the component can be overheated and thereby destroyed.
For these and other reasons there is a need for the present invention.